Myanmar’s “ethnic cleansing” of Rohingya Muslims is still going on, a senior UN human rights official claimed on Tuesday, more than six months after insurgent attacks sparked a security response that has driven nearly 700,000 people into Bangladesh.

Andrew Gilmour, the UN assistant secretary general for human rights, made the claim after a four-day visit to the Cox’s Bazar district in neighbouring Bangladesh, where he met people who fled Myanmar recently.

“I don’t think we can draw any other conclusion from what I have seen and heard in Cox’s Bazar,” Gilmour said.

After Rohingya insurgents attacked 30 police posts and an army base on August 25, Myanmar soldiers and police swept through villages in what the government says was a legitimate operation to root out “terrorists”.

Rohingya who sought shelter in Bangladesh have reported rape, killings and arson by security forces. The UN and US say the campaign amounted to ethnic cleansing.

Gilmour spoke to refugees who told of abductions by security forces and at least one apparent death of a Rohingya man in custody.

“It appears that widespread and systematic violence against the Rohingya persists,” Gilmour said.

Myanmar government spokesman Zaw Htay said he had not seen the UN statement published on Tuesday, but Myanmar was not committing ethnic cleansing.

“We don’t drive out the refugees,” he said.

Separately, the United Nations High Commissioner for Refugees said it was concerned about people living just inside Myanmar at its border with Bangladesh.

Residents of what is called “no-man’s-land”, as it sits outside Myanmar’s border fence but on its side of a creek that separates the two countries, say Myanmar officials have warned them on loudspeakers that their presence on the border line is illegal.

Zaw Htay said Myanmar had the right to move people from its territory and part of an agreed “buffer zone” with Bangladesh. Authorities had received information that “terrorists” linked to the August attacks on Myanmar’s security posts were sheltering there, he said.

Zaw Htay said he believed the people were staying on the border to “trap” Myanmar into conducting a “clearance operation”, which he said media and the United Nations would label as ethnic cleansing.